I read the Another manga before I watched the anime, and I can say confidently that the manga is 10s across the board for story, art, character development, and enjoyment. A few things are changed in the anime (I can't say what they are, because of spoilers), but not enough to make me enjoy it any less. The anime explains things just as well as the manga does, and the art is at the same level.
One of my favorite things about this anime is the character design. All of them are visually appealing, and even the minor characters are unique enough to be easily differentiated. Personality-wise, they are interesting and most of them have a well-developed background/character arc.
As for the plot, it is extremely confusing for the first few episodes, but everything begins to fall into place later on. This is certainly an anime that requires brain power, so if you're looking for a fluffy time-waster, go somewhere else (there's a whole genre for that type of thing).
The OP leaves a bit to be desired in subtlety, but that isn't this anime's strong point. The ED song is hauntingly gorgeous and worth a listen, even if you don't end up watching the anime.
Another is my favorite horror anime, and one of my favorites of any genre. Overall, it's about a 9.7 - 9.8. Definitely watch it if you're a horror fan. Even if you aren't, this one may change your mind.
